Capping and Devolumizing Classic Valve?

[factoid]

Can you do this mod without ruining the RT capability of your valve?

That's why I previously thought this was impossible with an RT style valve.

The way I understand the RT valve to work is that the full input pressure from the tank acts upon both the regulator AND the on/off valve. That high incoming pressure is what causes the on/off pin to be so forceful and push back on your finger, causing the bounce.

At the same time the air is also going through the regulator and then coming out at a lower pressure when it goes into the valve chamber.


If the pressure that goes into the air inlet is pre-regulated to 500psi (or whatever the correct operating pressure is) it won't have that higher pressure on the on/off.

If you're shooting an E/Pneu/EP Mag that might not matter, or maybe my understanding of the air flow mechanics is faulty.

[OPBN]

^^^ not a clue. I plan on using it on a classic valved pump.

[athomas]

factoid, you are correct. You can't modify a retro valve with this modification because of the different paths that the air takes.

[fierymartel]

DeuxMachina actually had a BST thread on here for the caps. I have one. I actually found it easier to adjust the velocity of the ball. I have an old mac dev regulator with 150-750 psi output. I am actually going to try to RT a classic valve with this. I believe if the dump chamber is devolumized in conjunction with a heavier spring and a ULT or RT on/off this might be possible. The goal is to achieve a high operating pressure without too high a velocity. Input welcome and all thread hijacking is purely incidental

[athomas]

High operating pressure in the chamber decreases reactiveness. Its the high pressure entering the valve that produces it. The pressure differential between the chamber pressure and the input pressure is what produces the majority of the reactivity. On capped valves, the regulator is external and all air coming into the valves is regulated so you reduce the pressure differential based on the fact that you are only using low pressure air at the input all the time. The air entering the chamber on a classic valve is already regulated which is why it is not as reactive as the retro valve. By removing the regulator and capping the valve, you don't change anything from the air pressure point of view. All the cap does, is remove part of the stainless regulator off the back half of the valve and relocate it somewhere else.

When you remove the regulator from a retro valve, you are removing the one thing that makes a retro valve reactive, which is the ability to provide full tank pressure directly to the top of the on-off pin. You will have a non-reactive retro valve, which is a essentially a classic valve.

[fierymartel]

Gotcha, air in dump chamber vs air pressure at on/off. Not going to be able to change that. I thought it was simply the high pressure at on/off. Thanks for the heads up.